Kitchen & Bath: Working With Mirrors

Sources of Supply

Kitchen & Bath: Working With Mirrors

Whether you simply hang a small oval in a gilded frame over
your sink, or cover every available inch of wall with
plate-glass mirrors, a bathroom doesn't look complete until the
mirror is hung. As part of our glazing business in Brewster,
Mass., my husband, Paul, and I cut and install numerous
plate-glass bathroom mirrors every year. With that experience,
we've developed good techniques -- along with definite opinions
-- for working with mirrors.

The multilayered process used to create mirror glass involves
an initial application of a sensitized layer of tin to the
glass, for adhesion. The second layer, of silver, is applied
for reflectivity, and a third, copper, layer is added to
protect the silver. The Guardian Industries mirror glass we
purchase (from Karas & Karas Glass in South Boston, Mass.)
is the best-quality American-made mirror available (see
"Sources of Supply" at end of article). These mirrors meet the
highest standards of the industry, are produced on
state-of-the-art equipment, and have a unique dual coating
applied over the reflective layering to resist silver corrosion
and "black edge," an undesirable flaw that characterizes
antique and not-so-antique mirrors alike. The primary coat that
protects and seals the silver and copper to the glass is
impervious to moisture penetration that could lead to silver
corrosion. To protect the primary coat, Guardian adds a
specially formulated scratch-resistant coat. This double-coat
backing greatly improves mirror performance and also helps
reduce the possibility of damage in transit.

When we go out to measure a job, we like to discuss the
aesthetic options and essential prep with either the homeowner
or the general contractor. Because we've done so many
installations, we've experienced almost every conceivable
problem that can arise.

Here's Looking at You

Wall-to-wall mirrors are effective at brightening the room and
making a small room feel larger. But if there's a toilet on the
wall of choice, we remind our customers that males in the
household may prefer not to stand before a mirror there.

Often, large bathrooms will have "his and hers" vanities
installed on opposite walls, which means that the two mirrors
face each other. We've done many of these installations in
recent years. The resulting "funhouse" effect does make the
room look bigger -- almost endless -- but it may be visually
disturbing to some folks (see Figure 1). If so, smaller,
task-sized mirrors will limit the effect. Mirrors are priced by
the square foot, so, unless there's a good reason (like an
insistent customer) to cover the walls, we suggest that the
money might be better spent elsewhere.

Figure 1.Opposing mirrors create a "funhouse"
effect, which may be delightful or disturbing, depending on the
client. An advantage is that a small bathroom can seem
larger.

Mirror Height

After checking the walls for plumb and the countertop or
backsplash that the mirror will sit on for level, we discuss
the height of the mirror. For example, if the customers want
the mirror to go all the way to the ceiling, we ask if they've
considered the task of cleaning the mirrors; in most cases, it
would require either a stepladder or a slippery climb onto the
vanity to reach the top. Another important consideration is
what the mirror will be reflecting. If there's a window on the
opposite wall, and the customers want the added light or view,
that's fine. But if there's only a blank wall or the upper half
of the bathroom door to reflect, why bother? Of course, we'll
do pretty much whatever our customers want, regardless of the
reason. On one job, the client, a mother of three "messy" boys,
wanted mirrors all the way to the ceiling and over much of the
walls because she thought it would be easier to constantly
clean mirrors than bare walls.

Light fixtures. The type and style of the lighting
fixtures also affect mirror height. We recommend going right up
to the base of a horizontal strip light but keeping the top of
the mirror slightly down from the base of a top-mounted
decorative fixture. If the light fixture has hanging globes or
shades, we like to keep the top of the mirror below the lowest
projection rather than tucked up behind; a mirror in that
position will reflect the back side of the globe or shade,
which tends to gather dust.

Cutouts. We can always drill right through the mirror
and mount the light fixture directly on the glass. The best are
sconce-type fixtures with an escutcheon that will cover the
hole in the mirror (which may not be pretty) by a comfortable
margin. If there's an outlet or switch right where we want the
mirror to be, we can sometimes incorporate it into the mirror
and cap it with a mirrored cover plate, giving the bathroom a
slick, custom look (Figure 2). One bathroom we did had mirror
entirely covering three out of four walls, floor to ceiling. It
was a very small room, and the idea was to make it look larger.
We had to drill holes for the toilet and sink supplies, along
with the light fixtures and all the outlets. Although we
accomplished the objective, I'd hate to have to clean that
room!

Figure 2. Existing outlets can be
incorporated into the mirror field and capped with a reflective
cover plate.

To make holes and cutouts in a mirror, we use a special
tripod-type drill press and an abrasive diamond-edged hole saw,
with a steady flow of water to cool and lubricate the cut
(Figure 3). We can cut hole diameters from 1/8 inch
up to 4 inches (used for most lighting fixture cutouts). To cut
an opening for a standard, rectangle GFI electrical outlet, we
drill two 2-inch-diameter holes, one above the other, and notch
the middle out with a scoring tool and a pair of nibblers
(Figure 4). Obviously, the measurements for electrical cutouts
must be dead accurate in order for the special mirrored cover
plate to cover the outlet holes. The cover plate dimensions are
slightly larger than standard-issue plastic covers, but you
still don't have much wiggle room.

Figure 4.To create a rectangular box opening, the
author drills multiple holes, then finishes the job with a
scoring tool and a nibbler.

Once we've cut the mirrors to size, we feed them through our
factory-edging machine to create an "aris" polished edge. An
aris polish has a slight bevel top and bottom, with the face of
the edge flat. After cleaning to remove the mirror dust, we
spray the freshly cut and polished edges with a sealer, a clear
coating specially formulated to help prevent silver
deterioration and the appearance of black edge.

Black Edge

Usually first seen at the bottom edge of a bathroom mirror,
black edge is caused by household corrosives, like glass
cleaner, toothpaste, or hand soap, pooling on the backsplash
ledge at the bottom edge of the glass. It's no different from
the tarnish that develops on silverware, except that it can't
be polished away. On lesser-quality mirrors that haven't been
edge-sealed after cutting and polishing, the edge can start to
deteriorate in as little as a month. We've also seen
discount-store mirrors or mirrored medicine cabinets, purchased
by our customers for their bathrooms, that began turning black
in the box.

Concealment. We recommend using a chrome-finish
aluminum J-channel at the base of any mirror that rests on a
backsplash (Figure 5). The 3/4-inch-high face of the
J-channel doesn't prevent the corrosion but does effectively
conceal it, as the black edge normally won't creep higher than
1/2 inch or so. Another advantage of using J-channel
is that it allows the installer to make spacing adjustments. If
an adjacent wall isn't plumb or the backsplash isn't level, we
can use small, clear vinyl shims inside the channel to slightly
tilt the mirror.

Figure 5. Chrome-plated J-channel
supports the mirror until the mastic sets up and hides shims,
but also conceals "black edge" corrosion on backsplash-mounted
mirrors.

There are always clients who reject the channel because they
want the mirror to stand alone. We can, and do, forgo the
channel if that's the case. Instead, we'll apply a thin bead of
clear silicone along the bottom edge to help prevent any
moisture from getting to the back of the mirror. That mirror,
once glued to the wall, isn't going to be easy to remove
(certainly not in one piece) and replace. For that reason, we
press the J-channel option. J-channel is available in almost
any conceivable finish to match the bathroom's decor -- brushed
nickel, brass, or white, for example.

We also use J-channel or L-channel to mount mirrors up off the
backsplash or vanity top. These aluminum extrusions are nailed
through the wallboard into the studs to support the weight of
the mirror. A piece of electrical tape over the exposed nail
heads prevents them from scratching the mirror backing. The
channel gives the necessary support to the mirror while the
mastic sets up, and helps ensure that the mirror doesn't creep
down.

Mirror mastic. To make sure the mirror stays where you
want it and that the mirror backing and coating aren't damaged,
you need to use a strong, appropriate mirror mastic. Other
adhesives may etch through the protective coatings and show
through in patterns of corrosion. We use Glazers Choice mirror
adhesive because of its extremely reliable hold, and we always
use more than is probably necessary, because we believe more is
better for this job (Figure 6). We've been called to jobs where
another company's mirrors have fallen off the wall because the
installers were too stingy with the glue. In one instance, our
client had just finished bathing her infant in the bathroom
sink and was walking out the door when the mirror fell off the
wall, hit the goose-neck faucet, and shattered, leaving a large
shard embedded in the floor. When we arrived to install the
replacement, I was appalled by the small daubs of glue the
previous installers had used for such a large mirror. We always
err on the side of caution, and, after 18 years in this
business, I'm proud to say that not one of our mirrors has ever
fallen.

Figure 6. Heavy mirror glass
calls for a generous application of special mirror mastic.
Drywall substrates must be dust free and sealed for a secure
bond.

The mastic is self-filling, which can be helpful in the case
of a slightly bowed wall. For a small inward bow, we can use a
thicker bead of mastic to build it out. But if the bow is
pronounced and protruding, the framing has to be corrected. We
check the wall planes for flatness with a long straightedge
during initial measuring to prevent this type of last-minute
snag. A mirror won't bend to conform to a severe outward bow
and, if you force it, will probably crack as soon as any
pressure is applied at either end, like during a simple
cleaning.

Surface prep. Mirror mastic requires a clean, dry
surface that is free of dust and dirt. Both the wall and the
mirror surface must be the same temperature to prevent
condensation. Porous surfaces, such as unpainted plaster,
drywall, or concrete, must first be sealed with a good latex or
acrylic primer before we can safely mount the mirror. If a
bathroom is to be wallpapered, we ask that the mirror locations
be left uncovered. Although mirror mastic will stick to
wallpaper, wallpaper glue isn't strong enough to hold the
weight of a mirror on the wall. The mastic sets up in about 20
minutes but attains full, 200-psi cure strength in 24 hours
under normal conditions.

We always get a great feeling of accomplishment when the
homeowner walks into a new bathroom and sees what a difference
the mirrors make.